1. Field of the Invention
The present invention relates to a cyclone separator for producing a swirl in a fluid to separate from the fluid a substance which has a density different from the density of the fluid. More specifically, the present invention pertains to a cyclone separator which can be advantageously adopted for separating liquid or fine particles of solids from gas, however, the present invention is not limited to such a use.
2. Description of the Prior Art
A centrifugal separator or a cyclone separator is well known in the art as a separator which is designed to introduce liquid tangentially into a cylindrical vessel to thereby produce a swirl of the liquid so that substances of different density can be separated from the liquid under an influence of centrifugal force produced in the fluid. There is another known type of separator which is designed to be specifically used for a water separator of an air conditioning system and to produce an abrupt change in the flow direction of the air so that water and fine solid particles can be separated from the air.
In the known types of separators, various proposals have been made in order to accomplish a high efficiency of separation. For example, the U.S. Pat. No. 3,843,126 proposes a separator which includes coaxially arranged inner and outer cylinders. Humid air is introduced into the inner cylinder from the bottom in a direction so that the air produces an upwardly directed swirl. The air having a higher water concentration is concentrated under the centrifugal force in the vicinity of the inner wall surface of the inner cylinder and a low pressure is produced in the center of the inner cylinder. The inner cylinder is provided with a plurality of radially extending vent tubes which have radially inner ends opened to positions adjacent to the center of the inner cylinder and radially outer ends opened to an annular space between the inner and outer cylinders. The low pressure produced in the center of the inner cylinder causes a suction to produce a circulation from the annular space through the interior of the inner cylinder and the upper end portion of the to the annular space. The air having a high moisture content flows along the inner wall surface of the inner cylinder and is carried by the aforementioned circulating flow into the annular space between the inner and outer cylinders. The water is then separated from the air and dripped into the bottom of the annular space.
The separator disclosed by the U.S. patent is considered to provide a high separating efficiency as compared with a simple cyclone separator, however, it is disadvantageous in that it is structurally complicated. More specifically, the separator has inner and outer cylinders and radially directed vent tubes must be provided to produce the circulated air flow. It should further be noted that the radially directed vent tubes cause an increase in the flow resistance to the air flow in the inner cylinder so that there will be produced a high pressure loss.